1. Technical Field
The present invention relates to smart grid distribution automation networks, and more particularly, to a metric for assessing the survivability of such network designs after a failure.
2. Discussion of the Related Art
Distribution Automation (DA) is a feature in power distribution networks to automatically detect, isolate and restore power after failure events. SAIDI (System Average Interruption Duration Index) is a very important measure of power reliability. It is a measure of customer average impact of system interruptions as it computes the sum of customer interruption durations over the total number of customers.
Traditionally, the reliability of power systems has been quantified using average metrics, such as SAIDI. Some of the United States public service commission's use SAIDI to assess utilities' compliance with the commission rules. SAIDI was developed to track manual restoration times, and according to Standard 166-1998, the median value for North American utilities is roughly one and a half hours. In smart grid networks, power failure and restoration events will have a finer level of granularity, due to the deployment of reclosers, which isolate faulty sections, and demand side management system activities, such as distributed generators and demand response application systems. Therefore, there is a need to extend the SAIDI metric, and to develop new models and tools for the accurate computation of customer interruption indexes after power failure events occur, even if the occurrence of such events is rare. The survivability of a mission-critical application is the ability of the system to continue functioning during and after a failure or disturbance.